You might have seen the Guerrilla warfare techniques in one of those Viet-war movies.The army men covering their faces with mud and hiding in the marshes. Many prisoners succeed every year in breaking the security despite of tight security and a number of cameras employed to monitor the surroundings, thanks to their stealth skills. Professor Kim Young of California State University at Fresno seems to have found the answer to this shortcoming in his "Doppler Radar." It uses the radar to spot a human, while the machine learning technique determines his/her current activity.
According to Young it is the “micro-Dopplers”, that help in uniquely tracking humans. Their different activities produce different micro-Dopplers patterns, which can then be ascertained by analyzing the spectrogram. So the prison guards can know whether their target is running or crawling on the ground. Unlike cameras, radar gives a better advantage to see through the walls or monitor a vast stretch of land. The technology is of great importance to army, which has to employ a large number of resources to monitor the border area. It can help in reducing the number of personnel required at such areas or at least improve the situational awareness. Another field where it can be helpful are the prisons where the radar can help detect the nocturnal activities of the prisoners trying to break free.